I know i can find them in hardware store, but i dont know what they look like, how much they cost, how big should i get for a California. ALso what do you use to cut them?
Weight rings are anything that add extra weight to the outer rim of the yo-yo.
The most common form is rubber o-rings that are placed under the lip of the yo-yo rim. This means thumb grinds will be impossible, but it will (in theory) improve the possible spin time of the yo-yo. It will also make the yo-yo heavier and many people don’t like that.
What size? whatever size fits… every yoyo is different, get the one that has the tightest fit under the lip of the rim.
If you aren’t absolutely maxing out the possible ability of the yo-yo already (note: you aren’t) then they really aren’t going to be a huge benefit to you… but if you want to add them, go for it… won’t hurt anything.
Other things can be used as well, but for simplicity nothing beats an o-ring.
Notice he didn’t post anything about cutting them.
As far as cutting them, i think he was referring to maybe metal and shaving it down to fit in the yoyo.